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B2b: A knit is a knit, right? Wrong.

Today’s subject is near and dear to my heart: Fabric. I love fabric. A lot. I confess to being a total fabric hoarder. I buy far more than I need, largely so that I can make pretty much any project that strikes my fancy without needing to wait on fabric.

So today, let’s talk about knit. That sounds like a pretty simple subject, but even within the narrower category of knits, there is so much variety that it can be completely overwhelming for a newcomer to the category. I’m going to do my best to decode some of this, but if you’re still confused or want a reference, I like the book Fabric A to Z by Dana Willard. It’s part of my collection, and is really handy when I’m not quite sure whether I can put that rayon crepe in the dryer, or what exactly IS georgette?

Just a disclaimer before we start (because ya know, I’m a lawyer and us lawyers love disclaimers): This is by no means meant to be a comprehensive guide. It’s meant as an introduction for those who are new to knits so that the jargon isn’t so scary. If you are looking for a comprehensive guide, please check out Dana’s book or one of the many other fabric resources out there.

There are two aspects of knits you need to understand to know how a fabric will behave: (1) fiber content and (2) stitch type. Let’s start with fiber content.

Fiber Content

This discussion is applicable to pretty much all fabric. Knits, like wovens, can be found in a variety of different fibers. The most common, and what I expect most will be working with in the Back to Basics series are (1) cotton, (2) rayon, (3) polyester, (4) Bamboo, and (5) a spandex blend. The other primary fibers would be silk and wool and various other natural fibers like hemp, but these knits are much pricier and while they would make beautiful t-shirts, they’re probably not what most of us will be working with.

1. Cotton. Ah, good ol’ cotton. It’s like an old friend — familiar and comfortable. Cotton is a natural fiber, made from the boll of the cotton plant. Cotton can perform differently depending on how it is woven or knitted, but in general, it tends to be stiffer with less drape than other fibers, unless blended with something else.

2. Rayon (also called Viscose). Rayon may be one of my favorite fibers to work with. It typically is soft and has beautiful drape. Rayon is technically a synthetic fiber, but it’s made from cellulose, often from wood pulp. Rayon, whether woven or knit, typically has a lot of drape and a very smooth hand. It is often used as a cheaper alternative to silk, as it will behave similarly. Rayon is frequently blended with cotton to give the cotton more drape.

3. Polyester. Polyester is a synthetic fiber made from both naturally-occurring as well as synthetic chemicals. A lot of RTW clothing is polyester or a polyester blend. Polyester can behave very differently depending on how it’s made and constructed. In my experience, polyester knits tend to pill a lot quicker than their natural fiber counterparts.

4. Bamboo. Yep, they make fabric from bamboo! Technically, this is a form of rayon, though you will almost always see it listed separately. In knits, it is typically blended with spandex. Bamboo is actually my favorite for t-shirts and tanks for several reasons. It has the softness of rayon, but the durability of cotton, and is thicker and very easy to work with. Bamboo is also naturally odor resistant, which makes it great for garments that get lots of wear.

5. Spandex blends. Spandex is a synthetic fiber that is incredibly stretchy and has amazing recovery. In fabric, you’re typically not going to find spandex by itself — it’s blended with other fibers to give them better elasticity and recovery. All of the fibers mentioned above are frequently blended with spandex, particularly in knit fabric. Spandex is frequently a good thing in knit fabric as it really, really helps with recovery — that is, making sure the fabric returns to its original shape after being stretched. Spandex is also known as Lycra or elastane.

Stitch Type

Not that any of us need more hobbies, but I have to say that I gained a much deeper understanding of knit fabrics when I started knitting. I had an intellectual understanding of these fabrics before then, but actually using needles and yarn to create my own fabric really helped me see how the fabric was made and how it would behave. Any of the fibers listed above can be found in the various stitches or fabric types below:

1. Jersey. Far and away the most common type of knit fabric. This is actually a really broad category that encompasses all kinds of other fabric types, like interlock (which is really just two layers of jersey knitted together) and double knit (like ponte). You can find jersey in any of the fibers I mentioned above. For those familiar with knitting stitches, jersey is knitted in stockinette stitch. If you look closely at the fabric, you can see that one side is all knit stitches (the “right” side) and the other is all purl stitches (the “wrong” side). Jersey also rolls at its edges or when cut, which can be a real PITA to work with.

2. Interlock. Technically interlock is a subset of jersey. It describes a fabric made up of two thin layers of jersey fabric that have been knitted together. As a result it has no “right” side, and does not roll at the edge. You will typically see 100% cotton interlock, though interlock can be made with any fiber and could have spandex blended in as well. Ponte is very similar to interlock, and is typically found in blends of polyester and rayon. And double knit is more of a generic term that encompasses both of these.

3. Rib knit. Rib knit is another kind of really stretchy knit. However, rib knit gets its stretch from how its knitted, rather than from the fiber. Ribbing is made by alternating knit and purl stitches — typically either 1 knit, 1 purl (1×1 ribbing) or 2 knit, 1 purl (2×1 ribbing). But I have also seen 2×2 ribbing (2 knits, 2 purls) and even 4×4 ribbing (4 knits, 4 purls), but those are much more rare. You frequently see rib knit used for neckbands and cuffs, though it is frequently used in tank tops as well.

4. Sweater knit. Sweater knit is really just a type of jersey, but knitted more loosely than most jersey. It’s nice and drapey, and contrary to popular belief, is perfectly appropriate for garments other than sweaters! Don’t get me wrong, it’s perfect for sweaters and cardis, but I also think that sweater knit looks really cute sewn up into a tank or basic tee.

What’s best for my t-shirt/cardigan/tank top?

If your Back to Basics week will include a pile of tees, tanks and cardigans, like mine will, you’re probably looking for cotton, rayon and bamboo jerseys, likely with some spandex. These jerseys are abundant and easy to find, have good stretch and recovery and will hold up to frequent wears and washes. Polyester is also easy to find, but it often doesn’t hold up as well to frequent wearing and washing. Not all polyester is created equal, and some is much higher quality than others, but often polyester will start to pill after a few washes and ends up all nasty-looking (that’s a technical term).

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10 comments on “B2b: A knit is a knit, right? Wrong.”

Excellent post. I like how you broke it all down and explained things in detail. Do you have any thoughts on bamboo knits with spandex/lycra? What about fabrics for leggings? Although I’ve bought a few knits and a serger I haven’t really used either :-/ Thank you!

I LOVE bamboo/spandex blends! They are actually my favorite for t-shirts and tanks because they’re naturally odor resistant. I edited the post to add a brief discussion on bamboo fiber — I debated whether to add it earlier and I think it needs to be there!

As for leggings, I tend to like cotton/spandex blends for those. They have nice stretch and good recovery and hold up well to washing. As much as I love bamboo, cotton/spandex has better recovery, which helps keep the knees from bagging out.

Actually, bamboo jersey is a form of rayon (or viscose as we call it in the UK) jersey. As you say Katie rayon is made from cellulose, which is derived from plants. Bamboo is a plant, and it is bamboo cellulose which is used in bamboo jersey. It is certainly very soft, but it is a soft form of rayon.

That’s technically true, though in my experience bamboo knits feel different than a more generic rayon knit. The reason I listed bamboo separately from rayon is because there has been some controversy lately, as well as some litigation, about bamboo being improperly marketed as sustainable and organic v rayon, etc.

Another good reason for listing bamboo as a separate category here, is that fabric retailers list the fabric content of bamboo rayon as “bamboo”, whereas other rayons/viscoses are listed simply as “rayon”. Until now, I was unaware that bamboo is a rayon, which is why I asked Kate her thoughts on bamboo fabric.

This is a great post! I’ve been sewing with knits for a couple years, but honestly hadn’t paid much attention to the content besides with or without spandex. Now I’ll be looking for some bamboo knits to try out. Thanks!